1. Field of the Invention
This invention relates to a filter connector for reducing electromagnetic interference. More particularly, it refers to a filter connector having a filter member with added ground planes which improve the capability of attenuating high frequency electrical signals from a conductive element.
2. Prior Art
Filters have been employed for decades to attenuate high frequency electrical signals, especially for military purposes. These filters have been relatively sophisticated and expensive. In recent years, the common usage of computers and particularly home computers has resulted in the generation of significant additional amounts of high frequency electromagnetic signals interfering with other electrical devices. For the purpose of reducing the output of such signals, the United States Federal Communications Commission (FCC) has promulgated regulations requiring attenuation at their source. See 47 CFR 15, Subpart J.
Available commercial filters employing ferrite sleeves (U.S. Pat. No. 4,144,509) or monolithic capacitors structures with or without ferrites (U.S. Pat. No. 3,538,464) are expensive for use in low-cost electronic equipment such as the personal computer. A need exists for an inexpensive filter connector that will satisfactorily attenuate electromagnetic signals at ultrahigh frequencies, i.e., up to 1000 megahertz (MHz). A useful commercial filter attenuates the electromagnetic signal at least 30 decibels (dB) at a 1000 MHz frequency.